Dental curing lights--maintenance of visible light curing units.

Successful curing depends directly on many factors of which the most important is the correct functioning of the curing unit to emit light of sufficient intensity and quality. If the contribution of any of these factors is at a less than adequate level, the light-sensitive materials will not polymerise completely, which in the long term may be responsible for secondary caries and decreased longevity of the restoration. Factors which may reduce the light output include ageing of the bulb and filter, damage of the light guide or fibre optics, deposits on the light tip due to composite build-up or autoclave scale, erosion of light tip surface due to immersion sterilisation, and line voltage fluctuations. Recent studies carried out to investigate the effectiveness of curing lights in clinical use show that most practitioners are unaware of the importance of routine monitoring, care and maintenance of curing lights. This paper reviews some of the available literature on the monitoring, care and maintenance of curing lights, including information on the influence that some of these may have on the intensity emitted by the curing light.